test.c

#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <allegro5/allegro.h>

const float FPS = 60;

void trace_handler(const char* str)
{
    fprintf(stderr, "%s", str);
}

int main(int argc, char *argv[])
{
    al_set_config_value(al_get_system_config(), "trace", "level", "debug");
    al_register_trace_handler(trace_handler);

    if (!al_init()) {
        fprintf(stderr, "Failed to initialize allegro.\n");
        return EXIT_FAILURE;
    }

   ALLEGRO_DISPLAY* display = al_create_display(640, 480);
   if (!display) {
       fprintf(stderr, "Failed to create display.\n");
       return EXIT_FAILURE;
   }

   ALLEGRO_EVENT_QUEUE* event_queue = al_create_event_queue();
   if (!event_queue) {
       fprintf(stderr, "Failed to create event queue.");
       return EXIT_FAILURE;
   }

   al_register_event_source(event_queue, al_get_display_event_source(display));

   bool running = true;
   while (running) {
       ALLEGRO_EVENT event;
       while(al_get_next_event(event_queue, &event))
       {
           if(event.type == ALLEGRO_EVENT_DISPLAY_CLOSE)
           {
               running = false;
               break;
           }
       }

       al_clear_to_color(al_map_rgb(0, 0, 255));
       al_flip_display();
   }

   al_destroy_display(display);
   al_destroy_event_queue(event_queue);

   return EXIT_SUCCESS;
}